Running hotter - options

[Mudderoy]

Ok summer time is here (90's in Houston today) and I need to pick one of three options soon to try and keep the engine temp down in the 210 range.

I have a high flow thermostat housing and 180 degree high flow thermostat.
I have a CFS 3 core radiator.
All the other things except for the heater core have been changed. (Ask if you don't believe me).

During some recent high RPM rapid acceleration starts, turns and stops I saw the temp gauge climb well above the 210.

This occurred after about 5 minutes of this type of driving.

After returning to normal driving and acceleration the temp dropped quickly to just above 210. So the 3 core is doing it's job.

I noticed this same behavior last summer while driving 70 to 75 mph on a trip. Temp would rise to about 227 during daytime driving. As the outside temps dropped so did the coolant temp.

Here is what I am thinking...

High flow thermostat housing and thermostat is allowing coolant to move around too quickly. (I doubt this is it, but possible)

Larger tires and heavier wheels are causing the transmission to heat up and that heat is being transferred to the coolant in the radiator. I have an factory transmission cooler but I am thinking about replacing it with one about 3 times it's size and surface area.

Replacing the mechanical fan with an electric fan. (This probably would have little effect on the temp while running at highway speeds.)

The radiator is full and a nice transparent lime green coolant color. The overflow bottle is spot on the mark hot.

Serpentine belt is tight and even set using a sbelt tensioning tool.

1) Replace thermostat housing and thermostat with standard flow
2) Replace small factory transmission cooler with a much larger one
3) Replace mechanical fan with electric fan (I'm going to do this eventually anyway. I like the idea of a constant air flow while sitting still or going slow.)

So I'm thinking the transmission cooler is my best bet. Whadda you think?

[BlueXJ]

Sounds like the first choice that I would pursue. The highflow should not affect that big of a temp shift. I would replace the t-stat with a slightly higher one such as the factory 195* one. You can send me the highfloe T-stat housing if you like. I want to try it on my Renix. Get a 1 ton tranny cooler from a Chevy/GMC truck they are huge and will also increase your tranny volume by nearly a quart. The added fluid will also dissipate heat.

[Mudderoy]

I got my thermostat housing and thermostat from Hesco. It wasn't very expensive. I might try a high flow 195 from them. More opinions may change my mind but right now I'm staying with the high flow stuff.

I bet the tranmission is getting hotter because of the tires/wheels and load. It happens quickly at higher speeds.

[BlueXJ]

Keeping the tranny cool has added benefits such as longer life and the capability to crawl all day without damages.

[DETOURS]

Yup, an external tranny cooler is always good.

Ever consider upgrading the water pump?

Also your clutch fan maybe free wheeling, the clutch alone can be replaced, would'nt bother with electric myself........

[Mudderoy]

Yup, an external tranny cooler is always good.

Ever consider upgrading the water pump?

Also your clutch fan maybe free wheeling, the clutch alone can be replaced, would'nt bother with electric myself........

clutch was replaced a couple of years ok, but it could be bad. Seems like it was $40 which is almost half the cost of an electric fan.

Back in my 327 days we just used a spacer and a different fan. No clutch issues ever again.

I want the Hesco high flow water pump, but $150 ouch.

I think I'll do the larger tranny cooler. $50 if I remember correctly.

[DETOURS]

Yea.....but the High Flow but is most likely intended to be used with their High Flow thremo housing.......the hi-flo thermo makes 'no' sense without a hi-flo pump.........:headshake:

The fan you refer to on the 327........would be a flex fan, the blades flex as the RPM's gain, creating LESS air draw............LESS air draw 'because' the vehical should be driving faster, forcing air through the radiator, cooling it, thus less 'fan' cooling is required.

Cooling is a low speed/idle kinda thing........thats where/when the fans do their work, creating air flow.

I'd go with the water pump, from there I'd consider moving the air out of the engine compartment by venting, or even just raising the rear of your hood,

[Mudderoy]

Yea.....but the High Flow but is most likely intended to be used with their High Flow thremo housing.......the hi-flo thermo makes 'no' sense without a hi-flo pump.........:headshake:

The fan you refer to on the 327........would be a flex fan, the blades flex as the RPM's gain, creating LESS air draw............LESS air draw 'because' the vehical should be driving faster, forcing air through the radiator, cooling it, thus less 'fan' cooling is required.

Cooling is a low speed/idle kinda thing........thats where/when the fans do their work, creating air flow.

I'd go with the water pump, from there I'd consider moving the air out of the engine compartment by venting, or even just raising the rear of your hood,

Interesting. I don't remember reading anything that said the high flow thermostat required a high flow water pump, but I follow the logic of it.

I have a hood in mind to do that, that I may get if this company does the website they were talking to me about. I may raise the rear of the hood for the Summer and see what it does.

Yeah Yeah flex fan, I couldn't remember the name.

[DETOURS]

A hi-flow thermo would 'not require the hi-flow pump, but it might be suggested that the hi-flow pump requires the hi-flow thermo...........follow?

Raising the rear of your hood is free, give it a shot, I run vents myself, but its more for the wheeling/idling/rock stress......not the street..

:popcorn:

[Mudderoy]

A hi-flow thermo would 'not require the hi-flow pump, but it might be suggested that the hi-flow pump requires the hi-flow thermo...........follow?

Raising the rear of your hood is free, give it a shot, I run vents myself, but its more for the wheeling/idling/rock stress......not the street..

:popcorn:

Yeah that makes more sense to me that the other way around.

I wish I had wrapped my exhaust header before I installed it.

[cher96]

I have:

3 Core H.D. Radiator
FlowKool HiFlow Water Pump
Turbo City HiFlow Thermostat Housing & Thermostat
Wrapped Exhaust Header
Remote Oil Filter
Oil Cooler
Transmission Cooler
Cowl Induction Scoop with a 12" diameter hole in hood

I have all these things installed on my XJ and I still hit 230 like I did yesterday. I live in Tampa, Florida. I'm at a loss as what to do next to try and keep it cool.

I have to change out the tranny fluid about every 6 months because it is burnt. I been thinking about adding another in tandem tranny cooler between my front bumper and just under the radiator because of this.

Frustrating.... just plain frustrating!

[DETOURS]

Vent your hood.

I placed mine up near the radiator, it helps, I've warmed up sticky buns on them in the past....

http://img.photobucket.com/albums/v649/Detours/100_3403.jpg

[cher96]

Spanky "D" I just LOVE the front of your XJ. Come on down to Tampa and do up my XJ up and we could do some serious Mudding and go to Busch Gardens or the Beach on the same day! LOL

[Mudderoy]

I have:

3 Core H.D. Radiator
FlowKool HiFlow Water Pump
Turbo City HiFlow Thermostat Housing & Thermostat
Wrapped Exhaust Header
Remote Oil Filter
Oil Cooler
Transmission Cooler
Cowl Induction Scoop with a 12" diameter hole in hood

I have all these things installed on my XJ and I still hit 230 like I did yesterday. I live in Tampa, Florida. I'm at a loss as what to do next to try and keep it cool.

I have to change out the tranny fluid about every 6 months because it is burnt. I been thinking about adding another in tandem tranny cooler between my front bumper and just under the radiator because of this.

Frustrating.... just plain frustrating!

Yep, 230 is about what mine does after 5 minutes at 80 mph. Mind you that is 3000 rpm on my 32" tires and 4.56 gears. Slow down to 40 mph and it is back down to about 212 after 3 mintues.

I would be :pee:'d if I had done all that and it still was running 230.

[cher96]

Before I did all these mods... I was running at 250+ in this Florida heat. I'm going to order one very long trans cooler for behind the bumper and bypass the radiator trans cooler altogether.

I use Royal Purple Synthetics for engine oil so I don't have to worry that my fluid thickens up when too cool or too thin when the engine gets too hot. I might put another oil cooler in too while I'm at it. IDK

[DETOURS]

Yep, 230 is about what mine does after 5 minutes at 80 mph. Mind you 32" tires and 4.56 gears.

Hate to suggest this, but theres part of your problem (32's/4:56).
A better balance up to 33's would'a been 4:10's.

[DETOURS]

Spanky "D" I just LOVE the front of your XJ. Come on down to Tampa and do up my XJ up and we could do some serious Mudding and go to Busch Gardens or the Beach on the same day! LOL

Thankyou, not big into mud though, I'll do the beach all day.......or rock. :thumbsup:

Maybe I'll do a "switching 2 round" write up.......

[cher96]

Thankyou, not big into mud though, I'll do the beach all day.......or rock. :thumbsup:

Maybe I'll do a "switching 2 round" write up.......

That would be AWESOME.... please do!